It has become commonplace to call Britain a “surveillance society,” a place where security cameras lurk at every corner, giant databases keep track of intimate personal details and the government has extraordinary powers to intrude into citizens’ lives.

A report in 2007 by the lobbying group Privacy International placed Britain in the bottom five countries for its record on privacy and surveillance, on a par with Singapore.

But the intrusions visited on Jenny Paton, a 40-year-old mother of three, were startling just the same. Suspecting Ms. Paton of falsifying her address to get her daughter into the neighborhood school, local officials here began a covert surveillance operation. They obtained her telephone billing records. And for more than three weeks in 2008, an officer from the Poole education department secretly followed her, noting on a log the movements of the “female and three children” and the “target vehicle” (that would be Ms. Paton, her daughters and their car).

It turned out that Ms. Paton had broken no rules. Her daughter was admitted to the school. But she has not let the matter rest. Her case, now scheduled to be heard by a regulatory tribunal, has become emblematic of the struggle between personal privacy and the ever more powerful state here.